1. Field of the Invention
The present invention relates to transferring context information contained in a web service invocation message. More particularly, the invention relates to a method and apparatus for transferring context information on a web server.
2. Description of the Related Art
Generally, an invocation or request between a plurality of web services is achieved by message transfer among a plurality of web services or applications. The term “web service” refers to web application based standard methods in which one web service invokes another web service by way of message transfer. Each web service is deployed in an application server such as a SOAP server, and each web service is performed through the application server.
The application server generally has the following functions: supporting the deployment and offloading of web services, monitoring network messages, receiving web service invocations or requests, parsing request messages, looking for web service programs to be invoked by request, transferring invocation parameters, performing web service programs, obtaining the process results of web services, packeting the results into standard web response messages, and sending messages to a requester.
FIG. 1 is a typical example of an interaction between a user and a plurality of web services. In this typical example, as shown in FIG. 1, a user first enters a user ID and password (PWD) through a local computer application to transfer them to web service 4. The user ID and PWD are authenticated and are judged whether they are authorized by web service 4, which is responsible for the authentication and authorization service. Web service 4 returns a message (token T1 for example) to the local computer application after the procedure of authentication and authorization is complete. After the user is successfully authenticated, the user may require a forum service. At this time, the user transfers the token T1 received from web service 4 to web service 1. When web service 1 receives the token T1, web service 1 also transfers the token T1 to web service 4 to validate it and obtains the result from web service 4, as shown in dashed line 4. When the user requires an incentive service, for example accessing web service 2, the token T1 is required to be transferred from web service 1 to web service 2. At this time, when web service 2 receives the token T1, web service 2 also transfers the token T1 to web service 4 to validate it and obtains the result from web service 4, as shown in dashed line 6. When the user obtains a core bank service, for example accessing web service 3, the token T1 is required to be transferred from web service 2 to web service 3. At this time, similarly, when web service 3 receives the token T1, web service 3 also transfers the token T1 to web service 4 to validate it and obtains the result from web service 4, as shown in dashed line 8. As will be appreciated, there are possibly more web services. In the procedure of accessing the above, the user transfers the token T1 from web service 1 to web service 2, transfers the token T1 from web service 2 to web service 3, and transfers the token T1 from web service 3 to an additional web service (not shown). The message transferred between two web services may further include a variety of parameters other than the token T1.
In the art, in order to transfer the message containing token T1 and parameters between web services, with respect to web service 2 for example, when web service 2 receives a message, it parses so as to obtain token T1 and parameters, and then applies the token to authentication and applies parameters to the service process of web service 2. When web service 2 sends a message to web service 3, it is required to rebuild a message containing the token T1 and parameters in the server of web service 2. Meanwhile it is required to obtain the message related to the token T1 and parameters. The parameters can be obtained from the entity of web service 2, while the token T1 is still obtained from the message that is transferred in the same manner as parameters, that is, the token T1 is passed through the process of web service in the same manner as parameters. The process is as follows:
Service1.operate (T1, parameter1, parameter2)
In the case of transferring the token T1 as described above, there is a need to provide such an interface process to solve the problem of transferring the token T1 and parameters together. If there is other information, the interface program needs to be modified to include other information. Thus, the process interface needs to be modified to add and process new information to be transferred whenever there is a need to transfer a piece of new information that is not a parameter type. The programmer needs to modify the interface endlessly, which increases workload. Thus, a method is desired that can reduce such load and guarantee the effective transfer of respective information.